package com.maozai.maozaimall.seckill.service.impl;


import com.alibaba.csp.sentinel.Entry;
import com.alibaba.csp.sentinel.SphU;
import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.maozai.common.to.mq.SeckillOrderTo;
import com.maozai.common.utils.R;
import com.maozai.common.vo.MemberRespVo;
import com.maozai.maozaimall.seckill.feign.CouponFeignService;
import com.maozai.maozaimall.seckill.feign.ProductFeignService;
import com.maozai.maozaimall.seckill.interceptor.LoginUserInterceptor;
import com.maozai.maozaimall.seckill.service.SeckillService;
import com.maozai.maozaimall.seckill.to.SeckillSkuRedisTo;
import com.maozai.maozaimall.seckill.vo.SeckillSessionWithSkus;
import com.maozai.maozaimall.seckill.vo.SkuInfoVo;
import com.baomidou.mybatisplus.core.toolkit.IdWorker;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RSemaphore;
import org.redisson.api.RedissonClient;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.BoundHashOperations;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;

import java.util.*;
import java.util.concurrent.TimeUnit;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

@Service
@Slf4j
public class SeckillServiceImpl implements SeckillService {

    @Autowired
    CouponFeignService couponFeignService;

    @Autowired
    StringRedisTemplate redisTemplate;

    @Autowired
    ProductFeignService productFeignService;

    @Autowired
    RedissonClient redissonClient;

    @Autowired
    RabbitTemplate rabbitTemplate;

    private final String SESSIONS_CACHE_PREFIX = "seckill:sessions:";
    private final String SKUKILL_CACHE_PREFIX = "seckill:skus";
    private final String SKU_STOCK_SEMAPHORE = "seckill:stock:";

    @Override
    public void uploadSeckillSkuLatest3Days() {
        //1 扫描最近三天需要参加秒杀的活动
        R session = couponFeignService.getLatest3DaySession();
        if (session.getCode() == 0) {

            List<SeckillSessionWithSkus> sessionData = session.getData(new TypeReference<List<SeckillSessionWithSkus>>() {
            });
            //System.out.println("sessionData => " + session);
            //缓存到Redis里面
            //1 缓存活动信息
            saveSessionInfos(sessionData);
            //2 缓存活动的商品信息
            saveSessionSkuInfos(sessionData);
        }

    }

    public List<SeckillSkuRedisTo> blockHandler(BlockException e) {
        log.error("getCurrentSeckillSkusResource被限流了");
        return null;
    }

    //返回当前可以参与秒杀的商品信息
    @Override
    @SentinelResource(value = "getCurrentSeckillSkusResource", blockHandler = "blockHandler")
    public List<SeckillSkuRedisTo> getCurrentSeckillSkus() {
        //1 确定当前时间属于哪个秒杀场次
        long time = new Date().getTime();
        log.error("资源被限流, {}", "getCurrentSeckillSkusResource");

        try(Entry entry = SphU.entry("seckillSkus")) {
            Set<String> keys = redisTemplate.keys(SESSIONS_CACHE_PREFIX + "*");
            for (String key : keys) {
                String replace = key.replace(SESSIONS_CACHE_PREFIX, "");
                String[] s = replace.split("_");
                Long startTime = Long.parseLong(s[0]);
                Long endTime = Long.parseLong(s[1]);
                if (time >= startTime && time <= endTime) {
                    //2 获取这个秒杀场次需要的所有商品信息
                    List<String> range = redisTemplate.opsForList().range(key, -100, 100);
                    BoundHashOperations<String, String, String> hashOps = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);
                    List<String> list = hashOps.multiGet(range);
                    if (list != null) {
                        List<SeckillSkuRedisTo> collect = list.stream().map(item -> {
                            SeckillSkuRedisTo redis = JSON.parseObject(item.toString(), SeckillSkuRedisTo.class);
                            //redis.setRandomCode(null); 当前秒杀开始了需要随机码
                            return redis;
                        }).collect(Collectors.toList());
                        return collect;
                    }
                    break;
                }
            }
        }catch (BlockException e) {
            log.error("资源被限流, {}", e.getMessage());
        }

        return null;
    }

    /**
     * 获取某一个sku商品的秒杀信息
     * @param skuId
     * @return
     */
    @Override
    public SeckillSkuRedisTo getSkuSeckillInfo(Long skuId) {
        //1 找到所有需要参与秒杀商品的key
        BoundHashOperations<String, String, String> hashOps = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);
        Set<String> keys = hashOps.keys();
        if (keys != null && keys.size() > 0) {
            String regx = "\\d_" + skuId;
            for (String key : keys) {
                boolean matches = Pattern.matches(regx, key);
                if (matches) {
                    String json = hashOps.get(key);
                    SeckillSkuRedisTo redisTo = JSON.parseObject(json, SeckillSkuRedisTo.class);

                    //随机码
                    Long startTime = redisTo.getStartTime();
                    Long endTime = redisTo.getEndTime();
                    long current = new Date().getTime();
                    if (current > startTime && current < endTime) {

                    }else {
                        redisTo.setRandomCode(null);
                    }

                    return redisTo;
                }
            }
        }

        return null;
    }

    //TODO 上架秒杀商品的时候，每一个数据都有过期时间
    //TODO 秒杀后续流程，简化了收获地址等信息的计算
    @Override
    public String kill(String killId, String key, Integer num) {
        MemberRespVo respVo = LoginUserInterceptor.loginUser.get();
        //1 获取当前秒杀商品的详细信息
        BoundHashOperations<String, String, String> hashOps = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);
        String json = hashOps.get(killId);
        if (StringUtils.isEmpty(json)) {
            return null;
        }else {
            //
            SeckillSkuRedisTo redis = JSON.parseObject(json, SeckillSkuRedisTo.class);
            //校验合法性
            Long startTime = redis.getStartTime();
            Long endTime = redis.getEndTime();
            long time = new Date().getTime();
            long ttl = endTime - startTime;
            //1 校验时间的合法性
            if (time < startTime || time > endTime) {
                return null;
            }else {
                //2 校验随机码和商品id
                String randomCode = redis.getRandomCode();
                String skuId = redis.getPromotionSessionId() + "_" + redis.getSkuId();
                if (randomCode.equals(key) && killId.equals(skuId)) {
                    //3 验证购物数量是否合理
                    if (num <= redis.getSeckillLimit()) {
                        //4 验证这个人是否已经购买过。幂等性；如果只要秒杀成功，就去占位。 userId_sessionId_skuId
                        //SETNX
                        String redisKey = respVo.getId() + "_" + skuId;
                        //自动过期
                        Boolean aBoolean = redisTemplate.opsForValue().setIfAbsent(redisKey, num.toString(), ttl, TimeUnit.MILLISECONDS);
                        if (aBoolean) {
                            RSemaphore semaphore = redissonClient.getSemaphore(SKU_STOCK_SEMAPHORE + randomCode);
                            boolean b = semaphore.tryAcquire(num);
                            if (!b) {
                                return null;
                            }
                            //秒杀成功，
                            //快速下单，发送MQ消息
                            String timeId = IdWorker.getTimeId();
                            SeckillOrderTo orderTo = new SeckillOrderTo();
                            orderTo.setOrderSn(timeId);
                            orderTo.setMemberId(respVo.getId());
                            orderTo.setNum(num);
                            orderTo.setPromotionSessionId(redis.getPromotionSessionId());
                            orderTo.setSkuId(redis.getSkuId());
                            orderTo.setSeckillPrice(redis.getSeckillPrice());
                            rabbitTemplate.convertAndSend("order-event-exchange", "order.seckill.order", orderTo);
                            return timeId;

                        }else {
                            return null;
                        }
                    }
                }else {
                    return null;
                }
            }

        }
        return null;
    }

    private void saveSessionInfos(List<SeckillSessionWithSkus> sessions) {
        sessions.stream().forEach(session -> {
            Long startTime = session.getStartTime().getTime();
            Long endTime = session.getEndTime().getTime();
            String key = SESSIONS_CACHE_PREFIX + startTime + "_" + endTime;
            Boolean hasKey = redisTemplate.hasKey(key);
            //缓存活动信息
            if (!hasKey) {
                List<String> collect = session.getRelationSkus().stream().map(item -> item.getPromotionSessionId() + "_" + item.getSkuId().toString()).collect(Collectors.toList());
                redisTemplate.opsForList().leftPushAll(key, collect);
            }
        });
    }

    private void saveSessionSkuInfos(List<SeckillSessionWithSkus> sessions) {
        sessions.stream().forEach(session -> {
            //准备hash操作
            BoundHashOperations<String, Object, Object> ops = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);
            session.getRelationSkus().stream().forEach(seckillSkuVo -> {
                String token = "";
                if (!ops.hasKey(seckillSkuVo.getPromotionSessionId() + "_" +seckillSkuVo.getSkuId().toString())) {
                    //缓存商品信息
                    SeckillSkuRedisTo redisTo = new SeckillSkuRedisTo();

                    //1 sku的基本信息
                    R skuInfo = productFeignService.getSkuInfo(seckillSkuVo.getSkuId());
                    if (skuInfo.getCode() == 0) {
                        SkuInfoVo info = skuInfo.getData("skuInfo", new TypeReference<SkuInfoVo>() {
                        });
                        redisTo.setSkuInfo(info);
                    }
                    //2 sku的秒杀信息
                    BeanUtils.copyProperties(seckillSkuVo, redisTo);

                    //3 设置上当前商品的秒杀时间信息
                    redisTo.setStartTime(session.getStartTime().getTime());
                    redisTo.setEndTime(session.getEndTime().getTime());

                    //4 随机码
                    token = UUID.randomUUID().toString().replace("-", "");
                    redisTo.setRandomCode(token);

                    String s = JSON.toJSONString(redisTo);
                    ops.put(seckillSkuVo.getPromotionSessionId().toString() + "_" + seckillSkuVo.getSkuId().toString(), s);

                    //如果当前这个场次的商品的库存信息已经上架就不需要上架
                    //5 使用库存作为分布式的信号量 限流；
                    RSemaphore semaphore = redissonClient.getSemaphore(SKU_STOCK_SEMAPHORE + token);
                    //商品可以秒杀的数量作为信号量
                    boolean b = semaphore.trySetPermits(seckillSkuVo.getSeckillCount());
                }
            });
        });
    }

}
